A foundation rests on

ANS:D - both (b) and (c)

A foundation typically rests on both the base of the foundation itself and the foundation soil beneath it. Therefore, the correct answer is: both (b) and (c) Explanation:

1. Base of the foundation: The base of the foundation is the lowermost part of the structure that directly contacts the ground or soil. It provides support and stability to the entire structure by distributing the load over a larger area and preventing settlement.
2. Foundation soil (subgrade): The foundation soil, also known as the subgrade, refers to the natural soil or ground upon which the foundation is built. It serves as the ultimate support for the foundation and transfers the loads from the structure to the underlying soil layers. The stability and bearing capacity of the foundation soil are crucial considerations in foundation design to ensure adequate support and prevent excessive settlement or failure of the structure.